Apparatus and method for communications testing

ABSTRACT

A communications connector tester for quickly and accurately analyzing communications connectors at production to determine whether the connectors are fit for use in certain communications applications is disclosed. Test signals at several discrete frequencies are sequentially inputted into pairs of conductors in the communications connector under test, and output signals are detected for the pairs under test. The output signals are compared to acceptable ranges for certain applications of the communications connector and the connector is passed or failed for certain applications based on the output signal values. Near-end crosstalk, far-end crosstalk, return loss, insertion loss, and other communications connector qualities may be measured using the present invention.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.11/423,848, filed on Jun. 13, 2006 which is a continuation of U.S.patent application Ser. No. 11/291,428, filed on Dec. 1, 2005 which is acontinuation of U.S. patent application Ser. No. 10/754,278, filed onJan. 8, 2004, which claims priority to U.S. Patent Application No.60/439,236, filed Jan. 10, 2003. These prior applications are herebyincorporated by reference in their entireties into the presentapplication.

FIELD OF THE INVENTION

The present invention relates generally to communications and morespecifically to a method of testing communications connectors quicklyand accurately at production.

BACKGROUND OF THE INVENTION

Communications connectors, where communication lines are connected toeach other and to network devices, represent an increasingly importantaspect of the communications industry. Communications connectors mayinclude pairs of conductors which are used as connection terminals forconductive twisted-pair communications cables. Though connectors arenecessary parts of a communications connection, they introduce a certainamount of signal degradation into communications signals. One type ofsignal degradation introduced by a connector is near-end crosstalk(NEXT), an error signal resulting from interference between pairs in theconnectors, with the error signal propagating backward from thedirection of signal flow into the connector. Far-end crosstalk (FEXT) issimilarly caused by interference between pairs and propagates in thedirection of signal flow through the connector. A third type of signaldegradation, return loss (RL) represents reflection of signal backwardfrom the connector due to impedance mismatches. Insertion loss is afourth type of signal degradation that represents signal loss throughthe connector in the direction of signal flow.

As the bandwidth of communications rises, the need for high-qualitycommunications connectors meeting tight requirements for reducing thesetypes of signal degradation increases. Concurrent with the increasingdemands on connector quality, the need for consistent testing ofconnectors to verify their suitability is increasing. One method fordetecting the amount of signal degradation introduced by a connector isto analyze a connector using a network analyzer. A network analyzercontains a transmitting port, which sends a test signal through aconnector or other device under test (DUT), and a receiving port, whichreceives signal from the connector. Electronics within the networkanalyzer analyze the returned signal relative to the transmitted signaland generate information about NEXT, FEXT, RL, and insertion losssufficient to determine the suitability of the connector.

Though network analyzers are accurate, they have significant drawbacks.One drawback of network analyzers is their speed. One NEXT test in acommon network analyzer takes approximately three seconds, and six testsmust be performed for each eight-conductor connector (one test each forconductors one and two, one and three, one and four, two and three, twoand four, and three and four). Thus, even assuming zero time forchanging pairs under test, a single connector will take eighteen secondsto test for NEXT using a network analyzer. Because the time delay fortesting using a network analyzer is longer than the time for productionof a connector, production line testing of all manufactured connectorsusing a network analyzer is impractical.

Another shortcoming of connector testing using network analyzers is thatnetwork analyzers generally operate in the common mode of signaltransfer rather than in a differential mode. Communication connectorsare generally designed to work in a differential mode. This differencerequires the use of a balun when testing connectors using a networkanalyzer. A balun is a device that converts a common mode signal to adifferential mode signal, and it adds a certain amount of noise anderror into the test results.

Because of these and other shortcomings of current connector testdevices and methods, there exists a need for a fast and accurate testprocedure and system for analyzing communication connectors.

SUMMARY OF THE INVENTION

The present invention includes a communications connector testing systemand method for testing communications connectors for compliance withstandards at speeds approximately equal to the speed of production ofthe communications connector.

Preferably, a communications connector testing system and method testscommunications connectors for one or more of return loss, insertionloss, near-end crosstalk, and far-end crosstalk resulting from testsignals input into the communications connectors.

According to one embodiment of the present invention, a communicationstesting system includes one or more oscillators for generating testsignals and inputting the test signals into a communications connector.Near-end detectors detect signals flowing opposite the direction of testsignal flow. Far-end detectors may be included to detect signals flowingaway from the communications connector. A microcontroller acceptssignals from the near-end detectors to determine values for near-endcrosstalk and return loss. The microcontroller may be further adapted toaccept signals from the far-end detectors to determine values forfar-end crosstalk and insertion loss. These values, either standingalone or in combination, are compared to acceptable values, and thecommunications connector under test is evaluated for suitability basedon this comparison.

Test signals and measurements may be emitted and taken sequentially toassure rapid evaluation of communications connectors under test.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other advantages of the invention will become apparentupon reading the following detailed description and upon reference tothe drawings in which:

FIG. 1 is a communications connector for use with the present invention;

FIG. 2 is a block diagram of a communications connector test deviceaccording to one embodiment of the present invention;

FIG. 3 is a block diagram of a communications connector test deviceaccording to another embodiment of the present invention;

FIG. 4 is a block diagram showing the incorporation of a communicationsconnector test device into a connector production line according to oneembodiment of the present invention;

FIGS. 5A and 5B are charts showing measurements made by time periods fora four-pair communications connector tested for return loss, near-endcrosstalk, insertion loss, and far-end crosstalk;

FIG. 6 is a chart showing measurements made by time period for afour-pair communications connector tested for return loss and near-endcrosstalk only;

FIG. 7 is a chart showing measurements made by time period for afour-pair communications connector tested for far-end crosstalk andinsertion loss only; and

FIG. 8 is a chart showing measurements made by time period for afour-pair communications connector tested for near-end crosstalk andfar-end crosstalk only.

While the invention is susceptible to various modifications andalternative forms, specific embodiments have been shown by way ofexample in the drawings and will be described in detail herein. However,it should be understood that the invention is not intended to be limitedto the particular forms disclosed. Rather, the invention is to cover allmodifications, equivalents, and alternatives falling within the spiritand scope of the invention as defined by the appended claims.

DESCRIPTION OF SPECIFIC EMBODIMENTS

The present invention is directed to quickly and accurately testingcommunications connectors. The principles of the present invention maybe applied to the testing of a variety of communications connectors,including communications jacks, cables, and plugs.

FIG. 1 shows an example of a communications connector 10 that may betested under the present invention. Although the present invention willbe described with respect to a four-pair communications connector 10,the present invention may be modified to test communications connectorswith more or fewer conductor pairs. The communications connector 10includes a socket 12 which contains eight contacts: a first contact 14,a second contact 16, a third contact 18, a fourth contact 20, a fifthcontact 22, a sixth contact 24, a seventh contact 26, and an eighthcontact 28.

For the purpose of communicating signals, the contacts may be groupedinto four pairs. According to one method for ordering the pairs ofconductors, a first contact pair 30 includes the fourth and fifthcontacts 20 and 22, a second contact pair 32 includes the third andsixth contacts 18 and 24, a third contact pair 34 includes the first andsecond contacts 14 and 16, and a fourth contact pair 36 includes theseventh and eighth contacts 26 and 28.

According to some embodiments of the present invention, communicationsconnectors may be tested at a number of discrete frequencies. Becauseerror response is approximately linear by frequency, test results atdiscrete frequencies can be generalized to determine whether aparticular communications connector is fit for a specific purpose.According to one embodiment of the present invention, a communicationsconnector test method and device is designed to determine whethercommunications connectors under test comply with the specifications forANSI/EIA (American National Standards Institute/Electronic IndustriesAssociation) Standard 568 Category 6 (“CAT 6”) communicationsconnections.

Turning now to FIG. 2, a test system 238 addressing the problemsassociated with quickly and accurately testing communications connectorsis shown as a block diagram. The test system 238 of FIG. 2 is designedto test communications errors likely to result during use of aparticular communications connector 210. In some embodiments, theconnector 210 may be the connector 10 illustrated in FIG. 1. However, asmentioned above, the present invention is not limited to connector 10but instead includes other connector configurations and numbers ofconductors. In the embodiment shown in FIG. 2, a test system accordingto the present invention can test for NEXT, return loss, FEXT, andinsertion loss. The test system 238 uses an oscillator 240, which may becontrolled by a separate oscillator controller 242, to send test signalsat certain frequencies to a switch array 244, which may in turn becontrolled by a switch array controller 246. For example, the oscillator240 may initiate testing by sending a test signal at 10 MHz to theswitch array 244.

The switch array 244 is designed to forward test signals to contactpairs of the communications connector 210. Once the test process hasbeen initiated, a near-end detector array 248 and a far-end detectorarray 250 operate to detect resulting signals from the communicationsconnector 210. Results from the near-end detector array 248 and thefar-end detector array 250 may be processed as individual results fromindividual detectors so that specific information can be gleaned as towhich contact pairs of the communications connector 210 generate errorsignals that fall outside acceptable ranges.

According to one embodiment of the test system 238, the switch array 244includes four switches: a first switch 252, a second switch 254, a thirdswitch 256, and a fourth switch 258. Each of these switches forwards theinput test signal to an associated differential amplifier, whichamplifies the signal for input into a contact pair of the communicationsconnector 210. In the embodiment shown in FIG. 2, a first amplifier 260,a second amplifier 262, a third amplifier 264, and a fourth amplifier266 are provided.

Each of the contact pairs is tested for the error signal caused by itsinteractions with each of the other contact pairs. Because error, suchas FEXT, induced in a second pair due to signal input into a first pairis the same as error in the first pair due to signal input into thesecond pair, there is no need to re-test a pair that has already beentested by inputting a signal into the second pair and detecting theresult in the first pair. For example, if a test signal has beeninputted into the first contact pair 230 and error results have beendetected in the second contact pair 232, there is no need to input thetest signal into the second contact pair 232 and test the results at thefirst contact pair 230, as this would be an effective duplication of themeasurement just completed.

In the example in which the oscillator 240 first sends a test signal at10 MHz to the switch array 244, the switch array 244 operates using thefirst switch 252 to forward the test signal to the first amplifier 260and onward to the first contact pair 230 of the communications connector210. With the test signal being inputted into the first contact pair230, a first near-end detector 268 and a second near-end detector 270are activated to detect backward-propagating signals, respectively, fromthe first contact pair 230 and the second contact pair 232. Thedetection of backward-propagating signal is accomplished using first andsecond near-end directional couplers 272 and 274 adapted to capture thebackward-propagating signal and forward this signal, respectively, tothe first and second near-end detectors 268 and 270. When the testsignal is forwarded to the first contact pair 230, the signal detectedby the first near-end detector 268 allows an analysis of return loss,and the signal detected by the second near-end detector 270 allows ananalysis of near-end crosstalk between the first contact pair 230 andthe second contact pair 232.

The detected signal is forwarded to a near-end analog-to-digitalconverter and controller 276, which converts the signal to a format thatcan be analyzed by a microcontroller 278. The microcontroller 278collects incoming information to compare against standards for operationof an acceptable communications connector, thereby enabling a decisionas to whether a particular communications connector passes or fails atest. The microcontroller 278 may make the comparison in combinationwith a computer connected via a CNC, a PC, or an RS232 connection asshown in FIG. 2. According to some embodiments of the present invention,a microcontroller may make comparisons and activate the productionequipment in response to the comparisons. As one example of a possibleerror reading, a 1.0 V test signal input into the first contact pair 230may induce a 0.5 V crosstalk signal at the second contact pair 232. Themicrocontroller 278 would then compare to 0.5 V crosstalk signal to areference voltage to determine whether or not the level of crosstalkmeets a given standard and hence to determine whether the connector isacceptable.

Continuing the example of a 10 MHz test signal being forwarded to thefirst contact pair 230, to complete the detection as to the first andsecond contact pairs 230 and 232 using far-end information, a firstfar-end detector 280 and a second far-end detector 282 are utilized todetect signals propagating along far-end signal paths. The first far-enddetector 280 measures a signal from a first far-end directional coupler284, and the second far-end detector 282 measures a signal from a secondfar-end directional coupler 286. The first and second far-enddirectional couplers 284 and 286 are adapted to measure a signalpropagating away from the communications connector 210. Signal at thefirst far-end directional coupler 284 may be used to determine insertionloss through the first contact pair 230, and signal at the secondfar-end directional coupler 286 may be used to determine far-endcrosstalk between the first and second contact pairs 230 and 232.According to one embodiment of the present invention, the signalscaptured by detectors in the far-end detector array are forwarded to afar-end analog-to-digital converter and controller 288, which convertsthe received signal and sends the converted signal to themicrocontroller 278. In the embodiment of FIG. 2, which is designed toanalyze near-end and far-end signals, the far-end signals terminate at atermination 290.

Simultaneously with detection and analysis of the near-end and far-endsignals relating to the first and second contact pairs 230 and 232, thetest system 238 analyzes signals resulting from the interaction of thefirst and third contact pairs 230 and 234 and from the interaction ofthe first and fourth contact pairs 230 and 236. That is, when the firstswitch 252 is activated to forward test signal to the first contact pair230, interaction of the first contact pair 230 can be measured inconnection with the third and fourth contact pairs 234 and 236simultaneous with measurement of the interaction with the second contactpair 232 and the return loss and insertion loss associated with thefirst contact pair 230. To analyze the interaction between the first andthird contact pairs 230 and 234, the first switch 252 is activated toforward test signal to the first contact pair 230, and a third near-enddetector 292 and a third far-end detector 294 detect signal captured,respectively, by a third near-end directional coupler 296 and a thirdfar-end directional coupler 298. Near-end and far-end interactionsbetween the first and third contact pairs 230 and 234 proceed asdescribed above with respect to the first and second contact pairs 230and 232.

To analyze the interaction between the first and fourth contact pairs230 and 236, while the first switch 252 is activated to forward testsignal to the first contact pair 230, a fourth near-end detector 293 anda fourth far-end detector 295 detect signal captured, respectively, froma fourth near-end directional coupler 297 and a fourth far-enddirectional coupler 299.

After the interactions between the first contact pair 230 and thesecond, third, and fourth contact pairs 232, 234, and 236 have beendetected and recorded, the test system 238 may proceed to alter thefrequency at which a test signal is input into the first contact pair230 or maintain the same frequency and progress to input the test signalinto the second contact pair 232. If the test signal frequency isaltered, testing proceeds as described above, but with a different testfrequency, such as 100 MHz.

Following input of the test signal into the first contact pair 230 andcollection of resulting signals from the first, second, third, andfourth contact pairs 230, 232, 234, and 236, the test system 238 hastested three of six possible interactions in a four-pair communicationsconnector 210. To test the remaining interactions, test signals must besent to different contact pairs. To test the interaction between thesecond contact pair 232 and the third and fourth contact pairs 234 and236, the second switch 254 is activated and the first switch 252 isdeactivated. When the second switch 254 is activated, the test signal isamplified by the second amplifier 262 and forwarded to the secondcontact pair 232.

Testing of the interactions between the second contact pair 232 and thethird and fourth contact pairs 234 and 236 proceeds similarly to theinteraction testing as described above. The second near-end detector 270detects backward-propagating signal to test for return loss when thetest signal is forwarded to the second contact pair 232. The third andfourth near-end directional couplers 296 and 297, respectively, forwardbackward-propagating signal to the third and fourth near-end detectors292 and 293 for an analysis of induced near-end crosstalk. The secondfar-end detector 286 detects forward-propagating signal to test forinsertion loss. The third and fourth far-end directional couplers 298and 299, respectively, send forward-propagating signal to the third andfourth far-end detectors 294 and 295 for an analysis of far-endcrosstalk.

Following the input of test signal into the second contact pair 232,with signal capture and analysis as discussed above, five of thepossible six interactions in a four-jack communications connector havebeen tested. Next, the third switch 256 is activated and the secondswitch 254 is deactivated to enable test signal to be amplified by thethird amplifier 264 and enter the third contact pair 234. With signalentering the third contact pair 234, the third near-end directionalcoupler 296 sends backward-propagating signal to the third near-enddetector 292 for an analysis of return loss at the third contact pair234, and the third far-end directional coupler 298 sendsforward-propagating signal to the third far-end detector 294 for ananalysis of insertion loss at the third contact pair 234. The fourthnear-end directional coupler 297 forwards backward-propagating signal tothe fourth near-end detector 293 for analysis of near-end crosstalkbetween the third and fourth contact pairs 234 and 236, and the fourthfar-end directional coupler 299 sends signal to the fourth far-end logdetector 295 for detection and analysis of far-end crosstalk between thethird and fourth contact pairs 234 and 236.

Following testing of crosstalk, return loss, and insertion loss withrespect to the first, second, and third contact pairs, test signal isinput into the fourth contact pair 236 for a measurement of return lossand insertion loss caused by the fourth contact pair 236. The fourthswitch 258 is activated, the third switch 256 is deactivated, and thetest signal is amplified by the fourth amplifier 266 and directed to thefourth contact pair 236. The fourth near-end directional coupler 297forwards backward-propagating signal to the fourth near-end detector 293for detection and analysis of return loss at the fourth contact pair236, and the fourth far-end directional coupler 299 sendsforward-propagating signal to the fourth far-end detector 295 fordetection and analysis of insertion loss at the fourth contact pair 236.

If test signal has been input into all four contact pairs and testinghas been conducted with respect to one frequency, the oscillatorcontroller 42 may activate the oscillator 40 at a new frequency forre-testing of the communications connector 10 at the second frequency.According to one embodiment of the present invention, testing isconducted at four discrete frequencies, though testing using more orfewer frequencies for each communications connector is contemplated.

Turning now to FIG. 3, an alternative embodiment of a test system 300according to the present invention is shown. In the embodiment shown inFIG. 3, an oscillator controller 301 controls the operation of severaldiscrete oscillators. These oscillators are designed to operate bysending test signals continuously at selected discrete frequencies. Inthe embodiment shown in FIG. 3, a first oscillator 302 emits a testsignal at a frequency of 10 MHz, a second oscillator 304 emits a testsignal at a frequency of 100 MHz, a third oscillator 306 emits a testsignal at a frequency of 200 MHz, and a fourth oscillator 308 emits atest signal at a frequency of 250 MHz. Oscillators emitting test signalsat greater or lesser frequencies may be used in alternative embodiments.Each of these signals is sent to a multiplexer array 312 designed toselect test signals and send the test signals to contact pairs at acommunications connector 310. The multiplexer array 312 may becontrolled by a multiplexer controller 314, which directs test signalsto contact pairs in a sequence. A first multiplexer 316 directs the asignal to a first amplifier 360, a second multiplexer 318 directs thetest signal to a second amplifier 362, a third multiplexer 320 directsthe test signal to a third amplifier 364, and a fourth multiplexer 322directs the test signal to a fourth amplifier 366. The amplifiersamplify the test signal and direct the test signal to respective contactpairs 330, 332, 334, and 336 of the communications connector 310.

Aside from the use of multiple oscillators and a multiplexer array togenerate and direct the test signals, the embodiment shown in FIG. 3operates similarly to the embodiment shown in FIG. 2. The specificembodiment shown in FIG. 3 is designed to measure only return loss andnear-end crosstalk, and is not shown with far-end detectors formeasuring insertion loss and far-end crosstalk, though an embodiment ofthe present invention using multiple oscillators and multiplexers andadapted to measure near-end and far-end signals is contemplated.Further, an embodiment of the present invention using a single, switchedoscillator and measuring only near-end crosstalk and return loss iscontemplated

Using test devices and methods according to the present invention,communications connectors can be tested very rapidly at production todetermine whether the connectors meet the requirements of certaincommunications specifications. For testing CAT 6 compliance, it ispreferred to have a range of test frequencies between one and 250 MHz,and four test frequencies spaced along this range have been found to bebeneficial. A test system according to one embodiment of the presentinvention is capable of testing all communications connectors producedat a production line for compliance with CAT 6 standards for NEXT andreturn loss.

For a connector to meet the Category 6 connector specification, it mustmeet the following criteria. The near-end crosstalk (NEXT) performancemust be greater then−54−20*log(F/100) in dB for a frequency range of 1to 250 MHz, with F as the frequency at any specific point in MHz. Thefar-end crosstalk (FEXT) performance must be greater then−43−20*log(F/100) in dB for a frequency range of 1 to 250 MHz. Thereturn loss performance must be greater then −30 dB for a frequencyrange of 1 to 50 MHz and greater then −24−20*log(F/100) in dB for thefrequency range of 50 to 250 MHz. Finally, the insertion lossperformance must be less then 0.02*sqrt(F) in dB for the frequency rangefrom 1 to 250 MHz. Again, F is the frequency at any specific point inMHz.

Because oscillators used in the present invention are not required tosweep through frequencies, the previously-known testing requirement fora phase-locked loop synthesizer is no longer necessary. Further, thetesting systems and methods of the present invention allow forsimultaneous testing of multiple contact pairs in a connector withoutthe need for physical switching of sensing from pair to pair, as when anetwork analyzer is employed. Though the present invention has beendescribed with respect to testing a connector jack, it is to beappreciated that the principles of the present invention could beapplied to the testing of connectors in patch cords, patch panels, wallplates, face plates, insulation displacement “110 blocks,” and to thetesting of communication cable.

Because of the test speed enabled by the present invention, testing forcommunication connector compliance with standards can be done for eachcommunication connector produced on a production line, allowing a testsystem to be integrated into the production line as shown in FIG. 4.FIG. 4 shows a tester 400 adapted to test a series of communicationsconnectors. According to one embodiment of the present invention,communications connectors are tested as they are produced on aproduction line. A machine controller interface 402 allows results fromthe tester to be used to halt production when a series of errors arediscovered by the tester 400, to alter production, or to removeparticular communications connectors 410 from production whensignificant faults have been discovered. The tester 400 and atermination 404 are designed to reciprocate in the direction shown byarrow “A” of FIG. 4 to enable connection and disconnection withcommunications connectors under test. FIG. 4 shows near-end crosstalkand/or return loss testing only; according to an alternative embodiment,another tester is coupled between the termination 404 and connectors 410to be tested to permit measurement of far-end crosstalk and/or insertionloss if desired. A test system according to some embodiments of thepresent invention enables testing of communications connectors usingdifferential mode signals, with no need to convert test signals to thecommon mode. According to one embodiment of the present invention,problems with communication connector production are identified duringproduction, so that communications connectors not meeting specificationswill be identified and rejected. Further, changes to improve performancemay be made during production.

Turning now to FIGS. 5-8, charts showing time periods necessary to makecertain measurements according to some embodiments of the presentinvention are shown. The charts of FIGS. 5-8 show time periods along theleftmost column and measurements made along the top row, with indicatorsat the intersections to show which measurements are made during whichtime periods.

FIGS. 5A and 5B show the measurements made during four time periods inan embodiment in which a communications connector with four contactpairs is tested for return loss, near-end crosstalk (NEXT), insertionloss, and far-end crosstalk (FEXT). Four test time periods, representingthe sequential input of test signals into pairs and the simultaneousreading of signals resulting from the test signal, are necessary to makethe measurements in this embodiment. In the first time period, returnloss and insertion loss resulting from pair one, and NEXT and FEXTresulting from the interaction between pair one and pairs two, three,and four are measured. In the second time period, return loss andinsertion loss resulting from pair two, and NEXT and FEXT resulting fromthe interaction between pair two and pairs three and four are measured.In the third time period, return loss and insertion loss resulting frompair three, and NEXT and FEXT resulting from the interaction betweenpairs three and four are measured. In the fourth time period, returnloss and insertion loss resulting from pair four are measured.

FIG. 6 shows the measurements made when a communications connectorhaving four contact pairs is measured for NEXT and return loss only.Four time periods are required in this embodiment. In the first timeperiod, return loss resulting from pair one and NEXT resulting from theinteraction between pair one and pairs two, three, and four aremeasured. In the second time period, return loss resulting from pairtwo, and NEXT resulting from the interaction between pair two and pairsthree and four are measured. In the third time period, return lossresulting from pair three, and NEXT resulting from the interactionbetween pairs three and four are measured. In the fourth time period,return loss resulting from pair four is measured.

FIG. 7 shows the measurements made when a communications connectorhaving four contact pairs is measured for FEXT and insertion loss only.Again, four time periods are required in this embodiment. In the firsttime period, insertion loss resulting from pair one and FEXT resultingfrom the interaction between pair one and pairs two, three, and four aremeasured. In the second time period, insertion loss resulting from pairtwo and FEXT resulting from the interaction between pair two and pairsthree and four are measured. In the third time period, insertion lossresulting from pair three and FEXT resulting from the interactionbetween pairs three and four are measured. In the fourth time period,insertion loss resulting from pair four is measured.

FIG. 8 shows the measurements made when a communications connectorhaving four contact pairs is measured for NEXT and FEXT only. Only threetime periods are required in this embodiment. In the first time period,NEXT and FEXT resulting from the interaction between pair one and pairstwo, three, and four are measured. In the second time period, NEXT andFEXT resulting from the interaction between pair two and pairs three andfour are measured. In the third time period, NEXT and FEXT resultingfrom the interaction between pairs three and four are measured.

Generalizing to the time periods required when measuring communicationsconnectors having different numbers of pairs of conductors, whenmeasurements of NEXT only, FEXT only, or NEXT and FEXT are made, thenumber of time periods (T) required for testing a communicationsconnector having P pairs is:T=P−1.

For a test procedure measuring return loss or insertion loss, or both,either alone or in combination with NEXT and/or FEXT, the number of timeperiods required is:T=P.

According to some embodiments of the present invention, testing timeperiods range from approximately 0.125 seconds to approximately 0.250seconds, though it is to be understood that alternative time periodranges may be employed in specific embodiments of the present invention.For example, time periods ranging from approximately 0.1 seconds toapproximately 0.5 seconds, or from 0.250 seconds to approximately 1.0seconds, may be advantageous in some embodiments of the presentinvention.

In addition to the ability to accept or reject the communicationsconnector based upon the testing results without stopping or slowing theproduction thereof, it is also useful as a process monitoring system. Bytesting each connector during the production process if the results aremoving in the direction of failure, connections may be able to beimplemented prior to the actual failure of any product thus avoiding theassociated waste involved.

While the present invention has been described with reference to one ormore particular embodiments, those skilled in the art will recognizethat many changes may be made thereto without departing from the spiritand scope of the present invention. Each of these embodiments andobvious variations thereof is contemplated as falling within the spiritand scope of the claimed invention, which is set forth in the followingclaims.

1. A method for testing crosstalk in a communication connector having aplurality of pairs of conductors, the method comprising: inputting atest signal at a first frequency into a first pair of conductors;simultaneously sensing: (a) a first frequency crosstalk signal betweensaid first pair of conductors and a second pair of conductors; (b) afirst frequency crosstalk signal between said first pair of conductorsand a third pair of conductors; and (c) sensing a first frequencycrosstalk signal between said first pair of conductors and a fourth pairof conductors; inputting a test signal at said first frequency into saidsecond pair of conductors; simultaneously sensing: (a) a first frequencycrosstalk signal between said second pair of conductors and said thirdpair of conductors; and (b) a first frequency crosstalk signal betweensaid second pair of conductors and said fourth pair of conductors;inputting a test signal at said first frequency into said third pair ofconductors; sensing a first frequency crosstalk signal between saidthird pair of conductors and said fourth pair of conductors; analyzingthe first frequency crosstalk signals; and determining whether saidconnector passes or fails the test based on the crosstalk signals. 2.The method of claim 1 wherein determining whether said connector passesor fails comprises comparing the crosstalk signals to acceptable rangesof crosstalk signals, passing the connector if the crosstalk signalsfall within the acceptable ranges, and failing the connector if thecrosstalk signals fall outside the acceptable ranges.
 3. The method ofclaim 1 wherein said first frequency crosstalk signals are near-endcrosstalk signals.
 4. The method of claim 1 wherein said first frequencycrosstalk signals are far-end crosstalk signals.
 5. The method of claim1 further comprising sensing first, second, third, and fourth returnloss signals from each of said first, second, third, and fourth pairs ofconductors and wherein determining whether said connector passes orfails comprises comparing said first, second, third, and fourth returnloss signals to acceptable ranges of return loss signals, passing theconnector if the return loss signals fall within the acceptable ranges,and failing the connector if the return loss signals fall outside theacceptable ranges.
 6. The method of claim 1 further comprising sensingfirst, second, third, and fourth insertion loss signals from each ofsaid first, second, third, and fourth pairs of conductors and whereindetermining whether said connector passes or fails comprises comparingsaid first, second, third, and fourth insertion loss signals toacceptable ranges of insertion loss signals, passing the connector ifthe insertion loss signals fall within the acceptable ranges, andfailing the connector if the insertion loss signals fall outside theacceptable ranges.